hi
is there any chance that you would be able to say
exactly how hard the water is please.
there are naturel ways of lowering your PH
rather than usings shop bought stuff.
can you say why your water is a problem to you.
:)

Might help to figure out if your source water (tap) is hard or if something in your tank is causing the water to become hard. Do you have lots of Limestone (AKA Holey rock) in your tank? What type of tank do you have? African Cichlids will thrive in hard water. I use an RO/DI to strip my water of minerals. I have such hard water (Central TX water filters through pure limestone) that we must remove all the diffusers, showerheads, aerators and such from all of our water sources once a month and soak them in vinegar to clean them. That's hard water. Imagine having to remove the hoses from your washing machine to pour vinegar into them and then run th emachine empty to flush the lines. A natural method would be to add loads of driftwood to your tank. It brings the PH way down to about 6.0 and will soften the water. You can also run peat in a canister filter. It will add tannins to the water, a tea or rust color, that can be removed with carbon.

i did do a water change. a few days ago and i havent tested since. i use my tap water which is a bit hard, but i cant get it to soften. i dont have any limestone or driftwood in the tank currently, but i had wood in not to long ago. in the tank i have guppies, 1 mollie, 1swordtail, 2catfish, 2platies, 1 iridescent shark(on the small side). they are all acting fine except for the shark. i dont think it is because of the water. he has been VERY unactive since the day i bought him. i dont think he needs a bigger tank since he is only a few inches long but i barely ever see him swiming around. if you have any advice on him i would like to know too. thanks.

hi
if the tank is too small then the fish can be stunted,
having said that i really don't know how long i have had
my clown loaches for,and they are still only a few inches,
and they are in a 240 lt tank.
some things can take a while to grow,when i looked up the shark
i forgot to see what the growth rate was,if i find it i'll let you know.
but i would go for the biggest tank you could or take it back to
the shop.